Traffic control apparatus



A. M. BALTAYAN ETAL 3,106,695 TRAFFIC CONTROL APPARATUS Oct. 8, 1963Filed May 14, 1958 4 Sheets-Sheet 1 FIG! PARENT STREET "c" s FIG. 3

STREET PARENT INV JOHN L. BARKER AND ARA M. BALTAYAN BY M Gkc0 ATTORNEYENTORS Oct. 8, 1963 A. M. BALTAYAN ETAL 3,

TRAFFIC CONTROL APPARATUS ONE CYCLE ONE CYCLE 2 |234 45s?s9|o|||2PHASE"A" RRRRGGYRRR s PHASE"B" e G Y R RR Re G Y R R LEFTTURNRRRGRRRRRRRRR ONE. CYCLE ONE CYCLE F IG. 4

2| 22 23 2&24 252627 28 29 303i 32 PHASE'U'NORTHRR R s as YR R R 66 YPHASE"C"SOUTH R R R R e G Y R R R s G Y PHASE"D" GGYRRRRGGYRRR INVENTORSJOHN L. BARKER AND ARA M. BALTAYAN BY C mw ATTORNEY Oct. 8, 1963 A. M.BALTAYAN ETAL 3, 06,695

TRAFFIC CONTROL APPARATUS 7 Filed May 14, 1958 4 Sheets-Sheet 3 IIIHI II I H Illlll Nil?! C14 I I I II I INVENTORS JOHN L. BARKER AND ARA M.BALTAYAN ATTORNEY l Cl2 Oct. 8, 1963 A. M. BALTAYAN ETAL 3,

TRAFFIC CONTROL APPARATUS 4 Sheets-Sheet 4 Filed May 14, 1958 PDX vo IFll F Q.

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INVENTORS BARKER AND ARA M. BALTAYAN BY Jigsaw? JOHN L.-

.ATTORNEY United States Patent 3,106,695 TRAFFIC CGNTROL APPARATUS AraM. Baltayan, New Haven, and John L. Barker, Norwalk, Conn, assignors, bymesne assignments, to Laboratory For Electronics, line, Boston, Mass, acorporation of Delaware Filed May 14, 1953, Ser. No. 735,236 19 Claims.(Cl. 3340-67) This invention relates to an improved tralfic signalcontroller, and more particularly to an auxiliary period timer of greatversatility, being easily and quickly converted from an actuatedauxiliary period timer to a non-actuated auxiliary period timer or viceversa.

In particular in the illustrative application the auxiliary period timeris used as an advance green timer although the auxiliary period timer isnot limited to such use. A11 advance green timer is a device well knownin the field of traffic control. It is a parasitic type device which isdependent upon a main traffic controller which, in such combination, issometimes referred to as a parent controller. During certain periods ofthe cycle of the parent controller, or upon actuation by t-raflic, theadvance green thner cooperates with the parent controller and insertsinto the cycle of the parent controller a period, controlled and timedby the advance green timer and during which a green signal isilluminated to one traflic flow, for example nonthbound, While thetraflic flow, in the opposite direction, for example southbound, is heldwith a red signal.

This advance green period terminates, without a clearance interval, byaccording n'ght-of-way in the usual manner by green signals to both ofsuch trafiic flows, or in other words to south and north approaches onthe same street in common. Thus the advance green period is insertedimmediately in advance of a regular two-way green period in the trafficsignal cycle for example.

In the non-actuated type of advance green timer for such purpose, theadvance green period is inserted in each signal cycle regardless of thepresence or absence of trafiic demand at such times, whereas in theactuated type of advance green timer the advance green period isinserted only in response to traflic actuation on one of the trafficapproaches.

In general the apparatus disclosed herein is a greatly improvedelectronic trafiic control device capable of use, in combination with atraiiic controller, as an advance green timer. The present invention ispresented in three units, including what is hereinafiter referred to as(1) a basic unit, (2) a plug-in jumper assembly and (3) a plug-in relayassembly.

By the addition of one of the plug-in assemblies to the basic unit, acomplete apparatus is formed either in the actuated form or thenon-actuated form, depending upon which plug-in assembly is employed.The combination of the basic unit and the plug-in jumper assembly formsa non-actuated auxiliary period timer while the combination of the basicunit and the plug-in relay assembly forms an actuated auxiliary periodtimer.

The unbalanced traffic movements caused in part by the increasing numberof vehicles on the road, occasionally cause much congestion at someintersections even though there is provision for control of normal andabove normal traffic.

Spasmodic diagonal trafiic flow across an intersection or unbalancedintersection trafiic flow, where a heavy left turn movement opposes onlyoccasional light straight through traific or where occasional light leftturn traflic is opposed by a heavy straight through traffic, presentproblems of which one solution is the staggered presentation ofright-of-way to such opposing t-rafiic flows.

The device herein proposed provides a time controlled output which maybe used to insert a right-of-way period into a cycle of an associatedtrafiic controller, which period may be used to stagger presentation ofright-ofway to the opposing traflic flows for a brief period, While thedevice itself may, by partly local adjustment and partly remote control,vary the time of the staggered presentation of right-of-way.

Both actuated and non-actuated forms, by varying the signals controlledby the output circuits are capable of a variety of difierent traificsignal control, as well as each form having remote selection between twolocally adjusted time controls.

A locally adjustable switch, in cooperation with the remotely controlledtime selector, may cause omission of the period of the auxiliary periodtimer and in the case of the actuated form, may cause an actuation,normally affecting the auxiliary period timer, to affect the parentcontroller as if the actuation had normally been received via the usualcall circuit of the phase of the parent controller with which theauxiliary period timer is associated.

Another locally adjusted, two position switch, associated with theplug-in relay assembly so that such switch is only available in theactuated form, selects between two difilerent types of response to theassociated traffic detector actuations.

It is therefore an object of the invention to provide an improvedelectronic means for inserting a timed signal period into the cycle of acyclic signal controller at a predetermined point in the cycle.

It is also an object to provide an improved trafiic control deviceeasily and quickly convertible from an actuated device to a non-actuateddevice through the interchanging of prepared plug-in assembly units inconnection with a basic unit.

It is a further object to provide an improved auxiliary traflic signalperiod control device providing for remote selections between twolocally adjusted timed periods therefor.

Another object is to provide an auxiliary trafiic signal period controldevice including means for elimination of such period with remotecontrol over such means of elimination of such timed period.

It is another object to provide an improved electronic advance greentimer.

An additional object is to provide an improved advance green timercapable of ready conversion from traffic actuated control to non-trafiicactuated control and viceversa.

A fiurther object is to provide an improved advance green timer withremote selection between two locally adjusted timing controls for suchadvance green period.

Additional objects will be apparent from a reading of the descriptionbelow.

FIG. 1 illustrates, in block form, an intersection controlled by aparent controller in cooperation with an auxiliary period timer with leit turn lanes for vehicle trafiic approaching the intersection fromopposite directions.

FIG. 2 is a signal sequence chart that may be associated with thesignals employed at the intersection illustrated in FIG. 1, for example.

FIG. 3 illustrates, in block form, an intersection with opposite traflicflows controlled by signal lights in such a manner that one direction oftrafiic flow is controlled only by the parent controller and theopposite trafiic flow controlled by the parent controller in cooperationwith the auxiliary period timer.

FIG. 4 is a signal sequence chart that may be associated with thesignals employed at the intersection illustrated in FIG. 3 for example.

HS. 5 is a schematic circuit diagram of a two phase, full-actuatedtratfic controller here used to represent the parent controller used incooperation with the auxiliary period timer.

FIG. 5a is a schematic representation of an alternate method of timingcontrol of the parent controller timing circuit that may be substitutedfor the form illustrated in the lower right part of FIG. 5.

FIG. 6 is a schematic circuit diagram, in the preferred form, of anon-actuated auxiliary period timer, with a terminal strip illustratedon the lower left for connection to the parent controller.

FIG. 7 is a schematic circuit diagram, in the preferred form, of theplug-in relay assembly unit, which unit, when plugged into thereceptacle illustrated in the lower part of FIG. 6, in lieu of theconnections illustrated connecting certain of the said receptacles ofFIG. 6, operates to convert the auxiliary period timer from anon-actuated unit, as presented in FIG. 6, to an actuated unit.

Referring to the several figures in more detail, FIG. 1 illustrates anintersection of street A and street B, for example, with the curb linesof the street formed by heavy dark lines. Employing compass directionssuch as the top of the diagram north; the bottom south and the left sideand right side west and east respectively, it may be said that in thesoutheast corner, represented by two boxes are a parent controller andan auxiliary period timer interconnected electrically by the lines asillustrated. The interconnecting lines are illustrated in detail below.

In street A formed by broken lines labeled BLN and 131.8 are specialleft turn lanes for vehicle traffic approaching the intersection alongstreet A, intending to negotiate a left turn at the intersection. It isexpected that through and right turn traffic will keep to the right onstreet A and left turn traffic will avail themselves the use of the leftturn lane.

In the left turn lane, formed by broken line BLN, for northbound vehicletraffic, represented by a rectangle labeled NLT, is a vehicle detectorwhich is connected to, and ends calls to the auxiliary period timer.Also, in this certain left turn lane represented by circles labeled LGand LR are two traffic signals, green and red respecrtively whichcontrol left turn tratlic in the northbound approach. Both these signalsLG and LR are connected to the auxiliary period timer by which they arecontrolled. Signal LG in the preferred form may be a green arrowindicating right of way to motorists who wish to execute a left turnfrom the northbound approach while signal LR may be a conventional redsignal indicating lack of right of way to motorists who wish to executea left turn from the northbound approach.

In the left turn lane, formed by broken line BLS, for southbound vehicletrafiic, represented by a rectangle labeled SLT, is a vehicle detectorconnected in parallel with vehicle detector NLT, to the auxiliary periodtimer. A green arrow signal, represented by a circle labeled LG isconnected in parallel with green arrow signal LG to the auxiliary periodtimer and red signal LR represented by a circle so labeled is connected,in parallel with the signal LR, to the auxiliary period timer. Thesignals LG and LR control the southbound vehicle tralfic in the leftturn lane formed by line BLS.

The vehicle detectors NLT and SLT are so situated in the respective leftturn lanes that a vehicle in such a lane will actuate the respectivedetector and that vehicles in the road to the right of the respectiveleft turn lane, presumably through and right turn traffic, will notactuate the detector in the adjacent left turn lane.

In the roadway of street A is a vehicle detector NVD, represented by arectangle. This vehicle detector is located in the right section of theroadway so that northbound .4 through and right turn vehicles willactuate the vehicle detector NVD. The vehicle detector NVD iselectrically connected to, and sends calls" to the parent controller.

Also illustrated in the northbound through and right turn traffic laneare three signals, represented by three circles labeled NSG, NSY andNSR, green, yellow and red signals respectively.

Signal NSG is connected to the auxiliary period timer by which it iscontrolled through cooperation with the parent controller all asdescribed below.

The signal NSY is illustrated connected to the parent controller bywhich the yellow signal is controlled.

The signals NSR' are illustrated connected to the auxiliary period timerthrough which the red signal is controlled in cooperation with theparent controller all as described below.

In the southbound through and right turn trafiic lane of the street Aintersection approach is a vehicle detector SVD which is connected tothe parent controller in parallel with the vehicle detector NVD.

A call to the parent controller via the vehicle detector NVD would bethe same as a call to the parent controller via the vehicle detectorSVD. Also illustrated in the said southbound lane are three circleslabeled NSG, NSY and NSR', representing the green, yellow and redsignals respectively used to control the southbound through and rightturn trafiic therein. The signal NSG is connected to the auxiliaryperiod timer in parallel with the signal NSG, both being identicallycontrolled. The signal NSY is connected in parallel with the signal NSYto the parent controller by which both signals are identicallycontrolled. The signal NSR' is connected in parallel with the signal NSRto the auxiliary period timer, both signals being identicallycontrolled.

Ln the street B westbound trafiic lane, at the approach to theintersection are three signals, represented by three circles labeledEWR, EWY and EWG. These signals, red, yellow and green respectively,which control westbound traflic approaching the intersection on street Bare connected to the parent controller by which they are controlled asare the corresponding red, yellow and green signals EWR', EWY' and EWGrespectively controlling eastbound trafiic approaching the intersectionon street B. The respective red, yellow and green signals are connectedto the parent controller over respective parallel circuits for identicalcontrol for each red, yellow and green signal on street B.

A vehicle detector WVD located in the westbound approach to theintersection along street B will be actuated by westbound vehicletraffic in that lane while vehicle detector EVD, located in theeastbound approach will be actuated by eastbound vehicle traffic eachapproaching the intersection on street B. Both these vehicle detectorsare connected in parallel to the parent controller to which they sendcalls.

It should be understood that FIG. 1 illustrates one type of trafiiccontrol system employing the auxiliary period timer in cooperation witha parent controller where a left turn traflic movement or two left turntrafiic movements are controlled at the same intersection.

By slight circuit modification of the external lighting control circuitsother modifications, resulting in other traffic control systems, may beobtained. For example, the signals LR and LR, the red signalscontrolling left turn tratfic may be "omitted entirely and the signalsLG and LG may be associated with the set of signals controlling therespective approach to the intersection so that a green left arrow isilluminated to accord advanced right-of-way to left turn traffic andupon the left turn green arrow being extinguished left turn vehicletratlic will look to the signals controlling through tratfic forright-of-way. This would allow left turn traffic an advancedright-of-way as well as additional right-of-way to proceed, if theirpath of intended travel is clear, during right-of-way to throughtrafiic. In such a control system the green arrow signal would generallybe placed with the group of signals controlling other trafiic in thesame approach so that all the signals would be together rather thanhaving one signal, the green arrow signal, separated from the other setof signals.

Referring to FIG. 2, a signal sequence chart is presented that may beassociated with the traffic control system illustrated in FIG. 1. Thesignal sequence chart of FIG. 2 includes two consecutive cycles of theparent controller, the first cycle being divided into seven periods, 1through 6, including 4a, while the second cycle is divided into sixperiods, 7 through 12. Below each numbered period 1 through 12,including 4a, in a box is a letter R for red, Y for yellow, or G forgreen, indicating the color of signal displayed during that period. Atthe left of the diagram is found the phase or traific flow to which thesignals at the right are displayed, Phase A represents the signalsdisplayed to through and right turn tratlic both northbound andsouthbound approaching the intersection on street A, but not left turntraific on street A, and Phase B represents the signals displayed to alltraflic whether eastbound or westbound on street B, and Left Turnrepresents the signals displayed to left turn traflic on street Awhether northbound or southbound at the intersection.

Periods l, 2 and 3, like periods 7, 8 and 9 respectively indicate red(R) signals displayed to all traffic except Phase B while Phase Breceives right-of-way in periods 1 and 2 and 7 and 8 via a green (G)signal and in periods 3 and 9 a yellow (Y) clearance signal. In period4a a green signal is displayed to Left Turn while red signals aredisplayed to Phase A and Phase B. The presence of period 4a indicatesthat a call for the green arrow signal was received and therefore thiswas inserted into the cycle before the normal period 4. Periods 4 and 5,like periods 10 and I l accord right-oflway to Phase A while Phase B andLeft Turn receive a red signal. Periods 6 and 12 are the yellow orclearance periods for Phase A While red signals remain displayed to allother trafiic.

It should be noted that right-of-way is not accorded to Left Turn in thesecond cycle. This cycle illustrates a signal sequence Without the greenarrow inserted into the cycle.

FIG. 3 illustrates an intersection of two streets, street C and street Demploying a traffic control system which differs somewhat from thefllustration in FIG. 1. It is obvious to those skilled in the art thatthe illustration in FIG. 1 discloses left turn traflic movement control.

As will be more fully described below, a preference is given, in theform of an advance green arrow signal, to left turn trafiic on street Awhile through and right turn trafiic on street A is held stopped.

FIG. 3, on the other hand presents the solution to a dilierent traflicproblem. If, for example, southbound traffic along street C in FIG. 3were generally heavy with a relatively heavy left turn trafiic movementfrom that quarter and northbound trafiic was generally light it wouldseem a proper solution to expedite the ilow of trafiic through theintersection by giving an advance right-of way signal to northboundtrafiic so as to clear the lesser northbound trafiic first and then giveright-ofway to southbound traflic and, in particular, the left turntraflic Without differentiating between through and left turn southboundtraflic from that quarter. This result is obtained by the use of atraffic control system illustrated with a parent controller representedby a box in the southeast corner with electrical connections to anauxiliary period timer represented by box so labeled. A vehicle detectorND, located in the northbound lane of street C is connected to theauxiliary period timer to which it sends calls.

The signals RS, Y S and GS, represented by circles in the northboundlane approaching the intersection on street 6 C control northboundvehicle traific in that quarter. The signals RS, a red signal; YS, ayellow signal; and GS, a green signal, are individually connected to theparent controller by which they are controlled.

A vehicle detector SD, located in the southbound approach to theintersection on street C is connected to the parent controller to whichthe vehicle detector SD sends calls.

The signals GS, YS and RS, green, yellow and red respectively,represented by the circles so labeled control the vehicle trarc in thesouthbound approach to the intersection on street C. The signals GS andRS are individually connected to the auxiliary period timer throughwhich they are controlled in cooperation with the parent controller. Thesignal YS is connected to the parent controller over a parallel circuitwith signal YS.

The vehicle detectors EWD and EWD' in the Westbound approach and theeastbound approach respectively are connected in parallel to the parentcontroller to which calls are sent. The signals SR, SY and SG, red,yellow, and green respectively, which control westbound trailic onstreet D approaching the intersection and signals SR, SY and 538, red,yellow and green respectively, which control eastbound vehicle trafilcapproaching the intersection on street D, are all connected to theparent controller by which they are controlled.

The signals SR, SY, SG, SR, SY and SG' of FIG. 3 correspond to signalsEWR, EWY, EWG, EWR', EWY' and EWG of FIG. 1 while detectors EWD and EWDof FIG. 3 correspond to WVD and EVD of FIG. 1 respectively.

Modification of the trafllc control system illustrated in FIG. 3 may beemployed to solve other traffic problems. For example trafiicapproaching the intersection along street C may be generally heavy withoccasionally heavy left turn tratlic from the northbound approach. Itmay be preferred to give an advance right-of-way to the entirenorthbound movement on street C while holding the southbound movementwhen one or more vehicles wish to execute a left turn from thenorthbound approach to the intersection. T'nis result may beaccomplished by modifying the trafiic control system of PEG. 3 toinclude a left turn lane to the northbound street C approach and bytransferring the vehicle detector ND (which is connected to theauxiliary period timer) to the left turn lane. An additional vehicledetector would be placed where vehicle detector ND is now illustrated,however, this added vehicle detector would be connected to the parentcontroller in parallel with vehicle detector SD of FIG. 3. With suchmodified traillc control system the actuation of the vehicle detector inthe left turn lane would send a call to the auxiliary period timer whileactuation of the vehicle detector in the through and right turnnorthbound approach lane would send a call to the parent controller aswould an actuation of vehicle detector SD.

FIG. 4, like FIG. 2, is a signal sequence chart, however, the sequenceof signals presented in FIG. 4 may be associated with the trafficcontrol system presented in 1G. 3. Like FIG. 2, FIG. 4 presents twoconsecutive cycles, one cycle including periods 21 through 26 includ ingan advance green period, period 240, and one cycle, periods 27 through32 omitting the advance green period.

At the left of the chart is indicated the phase or traflic flow to whichthe signals, represented by R for red, Y for yellow and G for green, atthe right are displayed. Phase C North refers to the northbound vehicletraific on street C approaching the intersection While Phase C Southrefers to the southbound vehicle trafllc on street C a preaching theintersection and Phase D refers to all the vehicle traffic, whethereastbound or Westbound approaching the intersection on street D.

Periods 2.1 and 22, like periods '27 and 28 indicate a green signaldisplayed to Phase D and a red signal to both Phase C North and Phase CSouth. Periods 23 and 29 indicate a yellow signal displayed to Phase Dwhile Phase C North and Phase C South receive a red signal.

Period 24a indicates a green signal as displayed to Phase C North whilea red signal is displayed to Phase C South and to all traffic on PhaseD.

Periods 24 and 25 are similar to periods 30 and 31 during which periodsa green signal is displayed to both Phase C North and to Phase C South,and a red signal is displayed to Phase D.

Period 26, like period 32 illustrates a yellow signal dis played toPhase C North and Phase C South while a red signal is displayed to PhaseD.

FIG. 5 is representative of the parent controller and is a part of atraffic control system and apparatus disclosed in United States PatentNo. 2,156,138, issued April 25, 1939, to Harry A. Wilcox and John L.Barker, but slightly modified for the purpose of the present inventionas described below. The use of the controller here shown is for purposesof illustration and is by no means an attempt to restrict the use of thepresent invention to combination with the controller of FIG. 5. Suchoperation of the present invention as described below is typical of theoperation with other trafiic controllers with which the presentinvention may be associated.

FIG. 5, as shown, is a form of two phase, full-actuated type trafficcontroller, representing for example a device named parent controller inFIGS. 1 and 3 above.

Ordinarily, a single controller of the form illustrated operatingindependently as a two phase, full-actuated controller transfersright-of-way cyclically or in response to actuation between the main andcross streets, the length of the cycle and the portions of theright-of-way signal cycle accorded to the main and cross streets beingdependent on, or modified by, actuation of the vehicle detectors in thestreets. The vehicle actuated detectors may be of any type as hereindiscussed.

The controller may, by manner of example, include a cyclic steppingmechanism having a plurality of contact pairs operated by a cam shaftwhich is moved step-bystep through a cycle by means of solenoid. Thecontact pairs control signal illuminating circuits and control circuits.

The solenoid in this embodiment is controlled from a timing circuitemploying a. capacitor-gas discharge tube combination permittingvariations in timing by the vehicle detectors as will be pointed out.Both minimum and maximum timing circuits are provided. The controller,it will be noted in FIG. 5, is arranged for operation from analternating current supply (indicated by a plus in a circle and a minusin a circle) and suitable voltage transforming and rectifyingarrangements are provided, as for example a. transformer XFR and athermionic rectifier VLV from which suitable potentials of directcurrent for operating the gas discharge tubes is obtained (at theterminals indicated by a plus in a square and a minus in a square).

The table at the right of FIG. 5 shows a development of the several camsC1 through C18 plus C29 through C22 and the positions of the cam shaft1' through 6' in which the various cams are operated to close theirrespective contacts. In each position of the cam shaft a circuit forcharging capacitor QA is completed over one of the interval adjustableresistances VA, IA, VB, IB, LA and LB, which are individually wired toone end of the resistor R1 while the other end is connected to thecapacitor QA which is then joined to the ground wire L2.

It will be noted that the present drawing, FIG. 5 here, differs from thepresentation in US. Patent No. 2,156,138 but a similar effect isobtained. Maximum timing capacitor QB is charged similarly overadjustable resistors MXA or MXB and through resistor R2 which isconnected to QB and then through to ground wire L2 as will subsequentlybe explained. Adjustable resistors MXA and MXB are shown in straightrather than arcuate form but are equivalent to those of the said patent.

Other modifications of the said patent form included in FIG. 5 areseveral signal lamps shown as internal parts for convenience, althoughin actual practice such signal lamps would actually be external to thecontroller. The two vehicle detectors of the said patent, DEW and DNS,appear in the present form as vehicle detectors WVD and NVDrespectively. The line L6 between terminal G and terminal 214 and lineL7 between terminal F and terminal 215 are additional modifications, theuse of which is described completely herein below. In the lower right ofthe circuit diagram in the present form, isolated by a box made inbroken line form, is an additional modification including terminal 219and terminal 216 with switch SW11 located between the two said terminalsand here illustrated as open. The terminals 0 and Q of the said patentillustration are here represented as connected to the ground wire L2while several interval timing resistors are shown in straight line formrather than arcuate form.

For purpose of illustration, circuits for the green signal and the redsignal of one phase, for example phase A, are illustrated as terminatingat terminals 211 and 213 respectively in the present form. It should beunderstood that during independent operation the respective signallights would be connected to the terminals 211 and 213 for illuminationin proper sequence, a green signal to 211 and a red signal to 213.

Operation of this controller as an independently operating full-actuatedcontroller will now be described.

Accordingly, under this type of operation the terminals 219 and 216would be connected via closure of switch SW11 while switches PB, hereillustrated as open, and PA here illustrated as closed, would both beopen.

Terminal G is connected through street A vehicle detector NVD togrounded power when the contacts of the detector are closed. Vehicledetector WVD for street B is connected between terminal F and groundedpower when the contacts of the detector are closed. Let it be assumed,for example, that the switches PA and PB are open, and at the moment thecam shaft is standing in position 6, the phase A or street A vehicleinterval.

It will be noted that in FIG. 5 herein, all switches including camcontacts are illustrated open except for switch PA, which is illustratedas closed. Although all cam contacts are illustrated as open, it shouldbe assumed that those cam contacts having a heavy black mark in line 6'in the shaft positions chart at the right of FIG. 5 are closed contacts.The several timing intervals corresponding to the shaft positions arehereinafter referred to as A yellow in position 1', B initial inposition 2, B vehicle interval in position 3', B yellow" in position 4',A initial in position 5', and A vehicle interval in position 6'. All therelays and the solenoid in FIG. 5 herein are initially deenergized inposition 6'.

Power is supplied from the A.C.+ power lead 20 through cam contact C11to grounded power L2 to cause the phase B (street B) red signal EWR tobe illuminated. AC. power is also supplied from 20' through close camcontact C9, here shown leading to line 211, which line is part of theilluminating circuit for the green signal NSG (shown in FIG. 1) of thephase A period. It is here assumed that independent operation wouldordinarily illuminate the green signal NSG (shown in FIG. 1) of thephase A, which would be connected between cam contacts C9 and groundlead L2 via the terminal 211.

Meanwhile capacitor QA is being charged by current from the rectifierVLV over D.C. plus lead L3, cam contact C4, a vehicle interval adjustingswitch VA, resistor R1, capacitor QA for timing A vehicle interval inposition 6.

It will be assumed that a succession of vehicles is passing overdetector NVD in street A resulting in intermittent operation of relay ERover a circuit from AC. input 2% through relay ER to terminal G, and viaclosed contact NVD to grounded lead L2. A circuit shunting 9 capacitorQA over low resistor YD on cam contact C is thus intermittentlycompleted through closed contact E2 from ground line L2, thus reducingthe charge on the capacitor QA to reset the vehicle interval timing andextend the A green period.

It now a vehicle arrives on street B and actuates the detector WVD therelay DR is energized by a circuit from the A.C. input 29 to relay DR toterminal F to closed contacts WVD to grounded lead L2. Relay DR isenergized and locks in over its contact DI, completing a circuit fromAC. input 2i? through relay DR, closed contact D1, cam contact C7 togrounded lead L2. Contact D2 is closed and completes a circuit fromgrounded lead L2 through contact D2, cam contact 06, through relay ARand tube FA paralleling capacitor QA. Also, contact D3 completes itstiming circuit to charge maximum timing capacitor QB from the D.C.+ leadL3 over cam contact Cl, contact D3, phase A maximum interval switch MXA,resistor R2, and capacitor QG to grounded power lead L2. The combinationof the variable resistor MXA and resistor R2 is substantially higher inresistance than the combination of variable resistor VA and resistor R1,so that the maximum time limit is considerably longer than the vehicleinterval.

Subsequently, due either to a gap of sufiicient size between actuationsby the street A traflic, permitting capacitor QA to become charged tothe flash potential or ioniz ing voltage of the tube FA, now completedin parallel with the capacitor, or due to the charge on the maximumcapacitor QB reaching the flash potential of tube FB, either tube FA orPE will become conducting whereupon either relay AR or DR, as the casemay be, is operated. At armature Al or B1 a circuit is thus completedfrom lead 20 through solenoid SR" to lead L2 while relay AR or :BR ismomentarily operated to energize solenoid SR. Energization anddeenergization of solenoid SR causes the cam shaft to be advanced by aratchet mechanism (not shown), to next position, position 1'.

As the maximum timing circuit is initiated upon actuation of thedetector in the lane not having right of way it assures that theactuating vehicle will be forced to wait at most no longer than theperiod of the maximum timing circuit before right of way is transferred.

In its energizing position the solenoid SR completes a circuit over itscontact S1, capacitor QA and low resistor YA, short circuiting capacitorQA so that whenever the solenoid operates to advance the cam shaft tothe next interval, timing will start with the initial capacitor voltageof substantially zero. Similarly, contact S2 completes a discharge forcapacitor QB over resistor YB. In position 1, cam contact C9 opens andcam contact C21 closes so that the phase A yellow signal NSY and thephase B red signal EWR are illuminated and the phase A green signal NSG(shown in FIG. 1) is extinguished. Capacitor QA is charged from lead L3over cam contacts C13, variable switch LA, resistor R1, capacitor QA andground lead L2. Tube FA and relay AR are connected across the capacitorover cam contact C6 and relay contact D2, and when the voltage ofcapacitor QA reaches the flash voltage of the tube PA, the relay AR andsolenoid SR are operated, and the cam shaft is advanced to position 2 inthe manner described above.

In position 2 the street A yellow signal NSY and street B red signal EWRare extingmished and the right of way is accorded to street B as camcontacts C20 and C22 are closed to illuminate phase A red signal NSR(shown in FIG. 1) through terminal 213 and phase B green signal EWG asshown in FIG. 5.

In order to provide a suflicient period for the starting up of any phaseB trafic which may be waiting, an initial non-extendible interval ofright-of-way is now timed. Capacitor QA is charged from the lead L3 overcam contact C14, adjustable resistor 13, resistor R1, capacitor QA togrounded lead L2 until the voltage across the capacitor reaches theflash potential of the tube FA,

iii

which then becomes conducting and causes the charge on the capacitor tooperate relay AR, and this in turn energizes solenoid SR" advancing thecam shaft to the phase B vehicle interval, position 3, while the signalshold.

Although there is no change in the signal indicating circuits at thisparticular time the relay DR holding circuit is broken at open camcontact C7. Relay DR had locked in over cam contact D2 to complete aholding circuit, as described previously to cam contact C7, and

now cam contact C7 is open and the circuit is broken de-energizing relayDR and opening contact D1. Now relay DR operates intermittently undercontrol of traflic on street B actuating the detector WVD, thusextending the right-of-way period in a manner similar to that describedfor relay ER by street A t-rafiic actuation in position 6. Also inposition 3, as in position 6', previously explained, the maximuminterval or the extendible vehicle interval shall terminate to operateeither tube PA or PR and cause the cam shaft to advance to the nextposition, 4.

Openation of the controller through positions 4 and 5' is similar .tothat described for positions 1' and 2 excepting, of course, that theright-of-way is leaving phase B tratfic in position 4' with the yellowsignal EWY illuminated by closure of cam contacts C10 and right-o f-wayis being accorded in position 5' to phase A trafllc for an initialnon-extendible interval. The charging circuit in position 4 extendsthrough cam contact C2 adjustable resistor LB, resistor R1, capacitor QAto grounded lead L2 for timing the clearance interval of phase B. inposition 5 the charging circuit is through cam contact C3, adjustableresistor IA, resistor R1, capacitor QA to grounded lead. At the end ofthe interval in position the initial interval of phase A, the cam shaftis advanced in a manner previously explained, into position 6 thuscompleting one entire cycle of the controller, whereupon the cycledescribed is repeated in accordance with the trafi'ic actuations.

If transfer of right-of-way from one road to the other at the end of thevehicle interval position 3 to 6' occurs by operation of the maximumtime circuit relay BR, contact B2 closes to place a controller incondition to remember vehicle cutoii so that the right-of-way will beretransferred :to them as soon as possible. This'is obtained bymomentarily connecting relay DR and ER. For instance, if right-o f-wayis on street B and waiting vehicle or vehicles on street A haveenergized and locked in relay ER, and if street B vehicle intervalposition 3 is terminated by operation of relay BR, a circuit to energizerelay DR is completed from the A.C. plus lead 29 to relay DR, contactB2, contact Ell, cam contact C18 '00 grounded power lead L2. Solenoid SRwhich operates immediately upon energization of relay BR provides atcontact S3 a lock-in circuit over contact D1 for relay DR, which holdsuntil the cam shaft has been moved to position 4, where the lock-incircuit over cam contact C7 becomes operative. If Tighter-way on streetA is terminated by operation of the maximum timing circuit, relay ER isleft energized to cause subsequent retransfer to street A.

The arterial or recall switches PA and PB when closed, insureright-of-way will return to the associated phase even in absence oftratfic thereon. Their effect, as will be seen from the circuit, is tosimulate operation of the detectors while their associated phase is notreceiving right-of-way, although they cannot produce any extensioneffect when their respective phase has rightof-way. By closure of onerecall switch, l or example, switch PA as illustrated, the controller ofFIG. 5 may he operated as a semiactuated controller, with street Adetector NVD disconnected from terminal G and relay ER operated only byswitch PA in cooperation with cam contact C18. Accordingly, whenright-of-way is transferred to street B for the duration of thepositions 2' and 3' the street B initial and vehicle intervalsenengization of relay i it ER by the circuit from the AC. power lead 26through relay ER, switch PA (when closed), cam contact C18 to groundedpower lead L2 causes right-of-way to be retransferred to street A byoperation of either the minimum or maximum timing circuits. Accordingly,in semi-actuated operation the right of way will normally remain onstreet A being transferred to street B for a predetermined minimumperiod in response to actuation of the street B detector WVD. Theright-of-way will remain on street B for an additional period if the-reare further actuations of the detector WVD within the maximum limit.However, right-of-way is then retransferred to street A from which itcannot again be transferred before expiration of a minimum periodcomprising the initial interval, position 5' and a vehicle interval,position 6 in which the minimum timing capacitor QA charges without anydischarge or resetting to the flash potential of its associated tube PA.

The independent operation of the trafiic signal controller representedin FIG. 5, having been described, which is similar to its operation as aparent controller in absence of actuation of the auxiliary period timer,it will now be described more fully how the said traific controller ofFIG. 5 is used in a traflic control system in coordination with [theauxiliary period timer, the subject to the present invention, inaccordance with the present invention.

Line L7 is connected between terminal F and lead 215 which lead isconnected in a manner described below to auxiliary period timer. Throughlead 215 a call for phase B is registered as described below, while lineL6 in FIG. 5 is connected between terminal G and lead 214, which lead isconnected to the auxiliary period timer to register a call for phase A,as described below, when the respective circuits to the auxiliary periodtimer are completed to ground.

In order that the timing of the cycle of the parent controller isstopped during the time of the inserted period, as later described, theswitch SW11, which has heretofore been assumed to be closed, is opened,as illustrated in FIG. 5, and the AC. input is connected through lead219 through certain contacts of the auxiliary period imer and throughlead 216 as is completely described below.

By opening or closing the contacts as the case may be, the auxiliaryperiod timer can either open or close the power circuit between lead 219and lead 216 and thereby control the timing of the parent controller bycontrol of the power operating the transformer XFR. Another method ofcontrol of timing shall be discussed hereinafter with reference to FIG.5a. The above described connections to control the power circuit to thetransformer XFR in the parent controller controls the timing in theparent controller and will eficctively increase the time of the cycle ofthe parent controller, whenever the auxiliary period timer inserts theauxiliary period into the cycle of the parent controller.

Other connections and reactions Within the auxiliary period timer havingadditional effect on parent controllers will become apparent by thedescription below.

FIG. 5a illustrates an alternate method or arrangement for externalcontrol of the timing of the parent controller during part of theoperation of the auxiliary period timer as described.

FIG. 5a in effect represents a modification of a part of FIG. 5, moredirectly, that part of FIG. 5 in the broken line box in the lower rightcorner of FIG. 5. With FIG. 5 modified as shown in FIG. 5a, the parentcontroller of FIG. 5 has its timing power supply circuit connectedbetween the input through line 26' to transformer XFR controlled by acontact TRI of relay TR which relay is externally controlled by theauxiliary period timer instead of having such power connection itselfextend externally through the auxiliary period timer. The modificationalso inverts the action of the means of stop timing, by having the relayTR energized 1.? to interrupt timing power, so that the external controlcircuit can operate this relay and thus the external circuit will beclosed only to stop timing. When the external circuit is open the relayTR is deenergized thus maintaining the contact TR]. closed.

FIG. 6 is a schematic circuit diagram of the preferred embodiment of thenon-actuated form of auxiliary period timer. The circuit of theauxiliary period timer as presented in FIG. 6 is composed of twosections, the basic unit, and the plugin jumper assembly unit. The basicunit is that part of the circuit diagram to the right of the broken lineBL and that part of the circuit diagram above the female receptacles F1through F14, but including the female receptacles. The plug-in jumperassembly unit, here illustrated as connected to, or plugged into, thebasic unit via male plugs N7, N9, N20 and N12, is shown below the femalereceptacles of the basic unit. The combination of the basic unit and theplug-in jumper assembly unit connected together as illustrated in FIG. 6form a non-actuated auxiliary period timer.

The basic unit presented in FIG. 6 may be converted into an actuatedauxiliary period timer by merely rcmoving the plug-in jumper assemblyunit illustrated in FIG. 6 and inserting into the female receptacles ofthe basic unit the plug-in relay assembly unit, illustrated in thepreferred form in FIG. 7, by plugging the male plugs of the plugin relayassembly unit, illustrated at the top of the circuit diagram of FIG. 7(labeled M1 through M14 exclusive of M12) into the corresponding femalereceptacles of the basic unit.

Generally, the non-actuated auxiliary period timer is illustrated withconnections to a terminal strip TS at the left of the diagram. Theterminal strip TS represents a common junction for the interconnectinglines between the auxiliary period timer and the parent controller. Abroken line BL indicates that the terminal strip TS is external to thecircuit of the auxiliary period timer.

A positive A.C. supply, on the order of volts for example, isrepresented by a plus in a circle with a common ground returnrepresented by a minus in a circle. A DC. supply, on the order of voltsfor example is represented by a plus in a square. A low voltage A.C.supply, on the order of 12 volts for example is represented by a plus ina circle in a square.

A potential divider PDX consisting of several resistors is connectedbetween the DC. supply and the common ground return.

Four relays TSR, RR, LTR and TR, all illustrated as deenergized,individually control the several contacts arranged below the respectiverelay.

Two potentiometers 35 and 36, each with a terminal labeled PD+ forconnection to a point on the potential divider PDX are illustrated justbelow the potential divider PDX. One potentiometer, as determined by therelay TSR, is selected for controlled charging of the timing capacitor33 through a circuit including several contacts and a limiting resistor37. The charging circuit, of which the potentiometers 35 or 36 form apart, is part of an electronic timing circuit which includes a dualtriode vacuum tube 39, capacitors 38, 40 and 41, resistors 44, 45, 46and 37 and relay TR. Although other types of timing circuits and/ormethods may be employed with similar effect and efiiciency the preferredembodiment employs this electronic timing circuit. The electronic timingcircuit employed herein is similar to that disclosed and claimed byPeter C. Brockett in his application No. 677,993, dated August 13, 1957,and assigned to Eastern Industries, Incorporated, the assignee of thepresent application. There are no claims made herein under theparticular type timing circuit per se.

Indicator lamps 47 and 48, used to indicate which potentiometer 35 or 36has been selected as part of the charging circuit for the capacitor 33are illustrated with 13 lamp 48 illuminated and lamp 4'7 extinguishedindicating potentiometer 3-5 is connected in the charging circuit.

In the lower right hand section of the diagram are four circles labeledLG, LR, GX and RX. These circles represent signal lamps with signals GKand RX, green and red respectively, associated with the parentcontroller, as explained below and signals LG and LR, green and redsignals respectively associated directly with the auxiliary periodtimer.

A vehicle detector, represented by a pair of open contacts labeled VD isillustrated below the signals with a switch 50 illustrated above thevehicle detector. The switch 50 may be a second vehicle detector or apushbutton.

The vehicle detectors herein referred to may be any of the well knowntype designed to close a pair of contacts. Such vehicle detector may beeither pressure or sound sensitive, magnetic, electronic or mechanical,d signed for use above, under or in the surface of the roadbed.

The several signals, the switch 56 and the vehicle detector VD are hereillustrated as internal parts for convenience although such parts areexternal to the circuit of the auxiliary period timer.

Referring momentarily back to 1, the green signals NSG and NSG' reilluminated by the same circuit as signal GX in FIG. 6 and therefore itmay be said that signal GX is similar to signals NSG or NSG. The redsignals NSR and NSR of FIG. 1 are illuminated by the same circuit assignal RX in FIG. 6 and therefore it may be said that signal RX issimilar to signals NSR or NSR. The signals LG and LG of FIG. '1 aresimilar to the signal LG of FIG. 6 while the signals LR and DR of FIG. 1are similar to signal LR of FIG. 6. The vehicle detectors NLT and SLT ofFIG. 1 are comparable to vehicle detector VD (or switch 50) of FIG. 6.

At the bottom of the circuit diagram in FIG. 6 are fourteen terminalslabeled F1 through F14 inclusive, which represents 14 individual femalereceptacles arranged to receive one of two plug-in assembly units,either/the plug-in jumper assembly here illustrated in FIG. 6 below thefemale receptacles or, in lieu thereof, to receive the plug-in relayassembly unit illustrated in FIG. 7.

A switch 49, the energizing illustrated in a broken line box 59 is incircuit for the relay TSR. The switch, here illustrated as an internalpast for convenience, is external to the circuit and is use-d for remotecontrol of the relay TSR being operated by a time clock, or some mastercontrol device, or manually.

A switch 51, with contact 51a closed and contact 511) open isillustrated below the indicator lamps. This switch is physicallyassociated with the potentiometer 35 so that when the adjusting knob ofthe potentiometer 35 is set in the oil position the contacts of switch51 are reversed. Full operation of the auxiliary period timer requiresthe contact 51a of switch 51 closed regardless of the condition of relayTSR or contact of switch 5-1 closed and relay TSR energized. The effectsof the reversal of switch 51 on the auxiliary period timer and theparent controller is explained below.

A description of the electronic timing circuit shall now be discussed.The electronic timing circuit is designed to energize the relay TR atthe end of a timed period by a rapidly increasing surging-lil e flow ofcurrent through the relay from the DC. supply through leads 55 and 56,the coil of relay TR, lead 57, plate 62-, cathode 63 (of tube 39), lead64, resistor 46 to grounded lead 75.

Normally, when the electronic timing circuit is inactive or when it istiming, prior to the end of its timed period, there is no current flowin the left side of tube 39 between plate 62 and cathode 63 because grid65 holds this section of the tube biased beyond cut-off. However, undersuch conditions current is flowing from id the DC. supply through leads55 and 56, the coil of relay TR, lead 57, resistor 44-, point 67,resistor 45, lead 66 to grounded lead 75. The amount of current flowingin this last described circuit is insufficient to energize the relay TR.

At point 67 a lead 68 is connected to obtain a potential for the grid 70of the right hand section of tube 39. In the last described circuit thecombination of resistors 44 and and the impedance of the coil of relayTR serves as a potential divider with the point 67 being particularlyselected so that the potential at point 67 is approximately 62% of the13.0. input. With such potential applied to the grid 70, plate currentwill normally flow from the DC. supply through leads and 69', plate 76and cathode 77 of the right hand section of tube 39, resistor 46 togrounded lead 75.

The left side of tube 39 is normally [held inactive ecause the potentialon cathode 63, connected to cathode 77 via load 64, is relatively highso that the bias of this tube section is high in absence ofcounteracting potential on the grid controlled by timing capacitor 38.

The capacitor 40, connected in shunt with resistor 46 serves to hold thecathode potential relatively steady. The capacitor 41, connected inshunt with resistor 45 normally serves to hold the potential on gridrelatively steady.

The capacitor 38 is a timing capacitor which applies any charge thereonto the grid 65, so that as a charge on capacitor 38 increases, thepotential applied to the grid 65 increases thereby reducing the cut-offbias of the lefit section of the tube. The timing capacitor 38 ischarged from the DC. supply through part of the potential divider PBX toa point PD+ through potentiometer 35, if relay TSR is deenergized sothat its contact 80 is closed or through potentiometer 36, if relay TSRis energized so that its contact '81 is closed, through lead 84, contactof relay LTR, contact 86 of relay RR,

' lead 87, resistor37 to capacitor 38.

The amount of time it takes to charge the capacitor '36 sufiiciently toapply a potential on the grid 65 to reduce the bias on the left half ofthe tube section above cut-off is determined by the amount of resistancein the charging circuit. By adjustment of the otentiometers 35 and 3 6which are calibrated to vary the period timed by the electronic timingcircuit on the order of 500,000

ohms per second for example, each potentiometer may permit a differenttimed period.

When the charge on the timing capacitor 38 becomes sufiiciently high,the cut-off bias on the left section of the tube 39' is overcome and theplate 62 begins to pass pl-aite current. In very rapid successivereactions the voltage drop across the coil of relay TR is increasedwhich reduces the voltage drop across the potential divider resistors 44and 4-5. This reduces the potential applied at point 67 and the grid 78.The reduction in the potential applied to the grid 76 reduces the platecurrent through the right section of the tube 39'. The reduction inplate current of plate 76 tends to reduce tithe cathode potential onboth cathodes which causes the left section of the tube to passadditional plate current through plate 62 which current is drawn throughthe coil of relay TR. With heavier current flow through the left side ofthe tube 39- the current flow through the resistors 4'4 and 45 isreduced which reduces the potential at point 67 thereby reducing thepotential applied to grid 70 thereby cutting off the plate current atplate 76. This results in a rapid surge of plate current through thetube 39 via plate 62 and cathode 63 thus causing the relay TR to becomeenergized. The energization of relay TR indicates the end of the timedinterval.

Referring now to FIG. 7, the preferred embodiment of the plug-in relayassembly unit is presented in schematic circuit form. At the top of FIG.7 labeled M1 through M14, exclusive of M12 a series of male plugs areillus- V trated which plugs are arranged to plug into the correspondingfemale receptacles, illustrated in FIG. 6, of the basic unit to combineto form an actuated auxiliary period timer.

Three relays DR, XR and LTD are illustrated as deenergized, with theirrespective contacts arranged beneath each relay. A capacitor 149 isconnected across the terminals of the relay DR to make the relay DR adelayed action relay. A double position ganged switch 150/15051, the useof which shall be explained below, is illustrated in its up positionwith contact 156 closed and 159a open.

Let it now be assumed that the auxiliary period timer, in its actuatedform is employed in a trafiic control system at an intersection such aspresented in FIG. 1, for example. The plug-in jumper assembly consistingof the male plugs N7 connected to N12 and N9 connected to N19illustrated plugged into the basic unit in FIG. 6 would now be removedand the plug-in relay assembly unit of FIG. 7 would be plugged into thebasic unit of FIG. 6 with the male plugs M1 through M14, exclusive ofM12 plugged into the respective female receptacles F1 through F14 withreceptacle F12 without an external connection.

Let it further be assumed that signal LG and LR of PEG. 6 represent thesignals LG and LG and LR and LR of FIG. 1 and that signals NSG and NSGof FIG. 1 are represented by signal GX of FIG. 6 while signals NSR andNSR of FIG. 1 are represented by signal RX of FIG. 6. Let it also beassumed that the vehicle detectors NLT and SLT of FIG. 1 are representedby vehicle detector VD of FIG. 6.

The connections between the auxiliary period timer and the parentcontroller will be assumed to be through leads 213, 211, 214, 215, 219and 216 as illustrated in FIG. 6. The lead 217 will be assumed notconnected for the present purposes.

Let it be assumed that the parent controller is at rest in its position6' of the cam shaft. This is the phase A or street A green restposition. In position 6' a green signal would be displayed to bothnorthbound and southbound trafiic on street A and a red signal toeastbound and westbound trafiic on street B and a red signal to anytraffic in the left turn lane, both north and south on street A. Thissignal display is indicated in periods 5 and 11 of FIG. 2. The lead 211from the parent controller would be energized from the A.C. input in theparent controller in FIG. 5 through lead cam contact C9 through lead 211to the junction on the terminal strip TS in FIG. 6 through lead 99,contact 91 of relay LTR, lead 94 to signal GX, the green signal forthrough md right turn trafiic, both northbound and southbound isilluminated. With the lead 211 energized the relay XR of FIG. 7 isenergized via a circuit that may be traced from the lead 211 through thejunction on the terminal strip TS in FIG. 6, through leads 90 and 95,female receptacle F5, male plug MS of FIG. 7, lead 96, the coil of relayXR, lead 97 to grounded lead 75, the gounded lead between FIGS. 6 and 7being joined by female receptacle F14 and male plug M14.

At this time the lead 219 would also be energized from the A.C. input inthe parent controller in FIG. 5 through lead 21)" and lead 219 to thejunction on the terminal strip TS in FIG. 6, through lead 98, contact 99of relay RR, contact 161 of relay LTR, lead 104 10 a junction on theterminal strip TS through lead 216 to the parent controller in FIG. 5through lead L10 to the transformer XFR. This last described circuit isthe power supply circuit for the transformer XFR from which the timingpower for the parent controller is obtained. When, as will be describedbelow, the auxiliary period timer inserts its period into the cycle ofthe parent controller and the contact 101 of relay LTR will open, withcontact 99 of relay RR closed, to interrupt the power supply to thetransformer XFR and stop the timing within the parent controller.

a green signal, to grounded lead 75. Thus r The signal LR, the redsignal of the left turn lanes of street A, is illuminated via a circuitfrom the A.C. supply, represented by a plus in a circle through leads105, 105 and 107, contact 198 of relay LTR, lead 109, signal LR togrounded lead 75.

To complete the signal display at the intersection of FIG. 1 a return toFIG. 5 is necessary where it will be found that the signal EWR isilluminated by the parent controller from the A.C. input through camcontact C11, signal EWR to grounded lead L2. The signal EWR in FIG. 5 iscomparable to the signals EWR and EWR of FIG. 1.

With the auxiliary period timer at rest the parent controller may cycle,as described above, without interference from the auxiliary eriod timer.In position 1 of the parent controller the lead 211 from the parentcontroller to the terminal strip TS will become deenergized by theopening of cam contact C9 of FIG. 5 and the signal GX of P16. 6 will beextinguished and the relay XR of FIG. 7 will become deenergized. Theyellow signal NSY, in FIG. 5, is illuminated to traffic on street A viaclosure of cam contact C21 in FIG. 5.

In position 2, 3', and 4 of the parent controller, the lead 213 will beenergized thereby energizing the relay RR in the auxiliary period timer.The energizing circuit for the relay RR would follow from the A.C. inputthrough lead 20 in FIG. 5, through cam contact C22 to lead 213 to thejunction on the terminal strip TS in FIG. 6 through lead 110, the coilof relay RR, lead 113 to grounded lead 75. With the relay RR energizedclosure of some of its contacts etfect the timing power circuit of theparent controller; the illuminating circuit for the signal LR; theilluminating circuit for the signal RX; a discharge circuit for thetiming capacitor 33 and prevents the possible charging of the capacitor38.

The contact 99 of relay RR is opened and contact 114 is closed so thatthe timing power circuit of the parent controller is completed from theA.C. input of the parent controller in FIG. 5 through lead 20', lead 219to the junction on the terminal strip TS in FIG. 6, through lead 98,contact 114 of relay RR, lead 104 to the junction on the terminal stripTS through lead 216 to the parent controller in FIG. 5, lead L10 to thetransformer XFR.

With closure of contact 115 of relay RR a circuit to shunt contact 1&3LTR is completed so that if the relay LTR would become energized to openits contact 108 the signal LR would remain illuminated via a circuitthat may be traced from the A.C. input through lead 105, contact 115 ofrelay RR, lead 116, lead 169 to signal LR to grounded lead 75.

The illuminating circuit for the signal RX may be traced from the A.C.input through lead 165, lead 106, contact 11 7 of relay RR, lead 118, tosignal RX to grounded lead 75.

A discharge circuit for the timing capacitor 38 is completed from thecharging side of the capacitor 38, through resistor 37, lead 37, contact119 of relay RR, lead 120 to grounded lead 75, and through leads 66 and71 to the ground side of capacitor 33. If there was any charge on thecapacitor 3 8 such charge would be dissipated through the dischargecircuit so that the charging of the capacitor 38 would begin with thecharge on the capacitor at substantially zero, with respect to ground.The charging circuit for the capacitor 38 is maintained open at opencontact 86 of relay RR.

In positions 5 and 6 of the parent controller, the lead 211 is energizedand the lead 213 is deenergizcd which causes the relay RR to becomedeenergized and the relay XR (FIG. 7) to become energized and extinguishthe signal RX and illuminate the signal GX, the circuit having beenpreviously traced.

With the parent controller in its position 6" and the auxiliary periodtimer at rest, let it now be assumed that a vehicle crosses over one ofthe vehicle detectors in one of the left turn lanes. With closure of thecontacts of the vehicle detector VD a circuit to energize the relay LTD(FIG. 7) is completed from the low voltage A.C. input (FIG. 6) throughlead 123, contact 124 of relay TR, lead 125, female receptacle F11, maleplug M11 of FIG. 7, lead 126, the coil of relay LTD, lead 127, lead 128,lead 129, contact 150 of switch Bil/150a, lead 130., lead 131, male plugM7, female receptacle F7 of FIG. 6, lead 133, contact 51a of switch 51,contact 134 of relay TSR, lead 135, female receptacle F9, male plug M9of FIG. 7, lead 136, male plug M13, female receptacle F13 of FIG. 6,lead 137, through vehicle detector contacts VD to grounded lead 75. Whenthe vehicle crosses over, and eventually off of the vehicle detector,the contacts VD will open to break the energizing circuit just recited,however, the relay LTD does not become .deenergized since the relay LTDlocks-in over its own contact 138. The lock-in circuit may be tracedfrom the low voltage A.C. input through lead 123, contact 124 of relayTR, lead 125, female receptacle F11, tmale plug M11 of FIG. 7, lead 126,the coil of relay LTD, lead 127, contact 138 of relay LTD to groundedlead 75.

The relay LTD closes its contact 139 and a circuit to energize the relayDR of FIG. 7, is completed from the DC. input in FIG. 6 through lead 55,female receptacle F1, male plug M1 of FIG. 7, lead 143, resistor 141 tocapacitor 140, which capacitor charges and thus delays the energizationof relay DR. When the capacitor 149 is charged (after approximately 40to 60 milliseconds, for example) the relay is energized from the chargedside of capacitor 140 through lead 144, the coil of relay'DR, lead 145,contact 139 of relay LTD, lead 146, contact 147, of relay XR, lead 148,lead 149 to grounded lead 75.

While the capacitor 140 is charging and before the relay DR becomesenergized a circuit is completed to the parent controller to supply aground connection for the relay DR (shown in FIG. thereby causing aphase B call to be completed to the parent controller so that the parentcontroller may be advanced in its cycle so that the parent controllermay move into position to have the auxiliary period'timer insert itstimed period into the cycle of the parent controller.

The circuit producing the phase -B call by energizing the relay DR (FIG.5) may be traced from the A.C. input in FIG. 5 through lead 20" to thecoil of relay DR through terminal F, lead L7 to lead 215, to thejunction of the terminal strip TS in FIG. 6, lead 1533, contact 154 ofrelay RR, female receptacle F4, male plug M4 in FIG. 7, lead 155,contact 156 of relay DR, lead 157, contact 158 of relay LTD to groundedlead 75. When the relay DR of FIG. 7 becomes energized the contact 156of relay DR will open to prevent any additional phase B calls being sentby the auxiliary period timer. This prevents any extension of the phaseB vehicle interval of the parent controller. I

With a call for phase B in the parent controller the parent controllermoves into its position 1, as previously described.

With the parent controller in position 1' the lead 211 is deenergizedand the relay XR becomes deenergized. The deenergization of relay XRopens contact 147 of relay XR which contact .is in the energizingcircuit for relay DR. Relay DR becomes deenergized and releases slowlybecause of capacitor 140 which discharges through the coil of relay DR,

When the parent controller advances into its position 2 the lead 213becomes energized so that the relay RR becomes energized via a circuitpreviously described. With relay RR then energized a circuit iscompleted to energize the relay DR in FIG. 7 from the DC. input in FIG.6 through lead 55, receptacle F1 to male plug M1 in FIG. 7 through lead143, resistor 141 to charge capacitor 140. When capacitor 140* becomescharged the relay DR becomes energized through a circuit that may betraced from the charged side of capacitor 140, through lead 144, thecoil of relay DR, lead 145, contact 139, of relay LTD,

lead 146, lead 159, male plug M3, to FIG. 6 and female receptacle F3,contact 160 of relay RR, lead 161 to grounded lead 75.

Between the energization of relay RR of FIG. 6 and relay DR of FIG. 7 acircuit is completed to supply a ground connection for the relay ER ofthe parent controller in FIG. 5 so that a call is put in to return theparent controller to phase A after phase B. This call circuit may betraced from the A.C. input in the parent controller in FIG. 5 throughlead 20', the coil of relay ER, terminal G, lead L6 to lead 214 which isconnected to the terminal strip TS in FIG. 6 through lead 164, contact165 of relay RR, con-tact 166 of relay LTR, lead 167, female receptacleF6 to FIG. 7, male plug M6, lead 168, contact 169 of relay LTD togrounded lead 75.

With the parent controller in its position 2., 3', and 4' the relay R-Rwill remain energized and, as previously described when the relay RR isenergized, the signal RX is illuminated through a circuit previouslydescribed. With both relays RR and DR now energized a circuit iscompleted to energize the relay LTR from the A.C. input in FIG. 6through lead 105, lead 170, the coil of relay LTR, lead 172, contact174, point 175, lead 176 to female receptacle F10 to FIG. 7, male plugM10, lead 177, contact *178 of relay LTD, lead 179, contact 1811 ofrelay DR, lead 183, lead 149 to grounded lead 75'. When the relay LTR isenergized it closes its contact 173 which shunts contact 174 of relayR-R from the lead 172 to point 175 so that the relay LTR locks inthrough its own contact 173. Contact 85 of relay LTR is closed toprepare the charging circuit for the capacitor 38; contact 184 of relayLTR is also closed to shunt contact 117 of relay RR when contact 117opens as relay RR becomes deenergized thus the signal RX will remainilluminated; contact 1118 opens so that the signal LR will beextinguished as contact 115 of relay RR opens; contact 101 is opened sothat the timing power supply circuit of the parent controller will beopened when the relay RR becomes deenergized and opens its contact 114and closes its contact 99; and contact 91 of relay LTR opens to preventthe illumination of signal GX when the lead 211 becomes energized whilecontact 185 of relay LTR closes to prepare a circuit for theillumination of signal LG.

When the parent controller advances into its position 5 the lead 213becomes deenergized as cam contact C22 of FIG. 5 opens. The relay RRbecomes deenergized and opens its contact 119 and closes its contact 86thus completing the charging circuit for the capacitor 38 as previouslydescribed.

The contact 117 of relay RR opens but is shunted by closed contact 184of relay LTR to maintain the illumination of signal RX. The contact 99of relay RR is closed but the power supply circuit for the parent timing'is broken at open contact 101 of relay LTR.

With the power supply circuit now open the timing within the parentcontroller stops and the parent controller is held suspended while theauxiliary period timer controls the signals giving right-of-way at theintersection. The contact 160' of relay RR, in the energizing circuitfor the relay DR is open but the relay XR is now energized since thelead 211 from the parent controller is energized thus energizing therelayXR which relay closes its contact 147 to complete a parallelcircuit to ground for the relay DR as previously described.

With the lead 211 energized the signal LG is illuminated by powerapplied through the energized lead 211 through the junction on theterminal strip TS, lead 90, contact 185 of relay LTR, lead 188, signalLG to grounded lead '75.

At the termination of the period as determined by the charge in thecapacitor 38 the tube 39 will pass plate our rent between plate -62 andcathode 63 and energize the relay TR. The relay TR will open its contact124 and break the energizing circuit for the relay LTD of FIG. 7

thereby causing the relay L'ID to become deenergized.

139 to cause the The relay LTD will open its contact 178 relay DR tobecome deenergized, and open its contact to cause the relay LTR tobecome deenergized.

With the relay LTR deenergized the contact 185 opens to extinguishsignal LG and contact 91 closes to illuminate signal GX from energizedlead 211. The contact 187 of relay LTR opens and contact 101 of relayLTR closes to complete the power supply circuit for the timing power ofthe parent controller. Contact 184 of relay LTR opens to extinguish thesignal RX while contact 108 closes to illuminate the signal LR throughcircuits as previously described.

When the relay LTR becomes deenergized the contact 85 opens to interruptthe charging circuit of the capacitor 38. Prior to deenergization ofrelay LTR the capacitor 38 discharges somewhat through the tube 39 fromthe grid 65 to cathode 63, lead 64, through resistor 46 through groundlead 75, lead 66, lead 71 to the capacitor 38 while the left section oftube 39 was conducting. The bias of the tube section including plate 62,grid 65 and cathode 63 is increased to cutoff and the current flowthrough this section is blocked. The right section of the tube includingplate 76, grid 70 and cathode 77 resumes normal current flow and theflow of current through the relay TR is reduced thereby deenergizing therelay TR.

With relay TR deenergized the contact 124 closes and the auxiliaryperiod timer now clear of all calls awaits further calls of trafiic.

The operation of the actuated auxiliary period timer has been consideredwith the switch 150/ 150:: in its up position with contact 150 closedand 150a open. With the switch 150/ 150a in its up" position it has beenseen that the only call via the vehicle detector VD that efiects theparent controller is the call that energizes the relay LTD of FIG. 7.Any subsequent call, while the relay LTD is energized is blocked in thecircuits of the auxiliary period timer. If, when the switch 150/15011 isin its up position a call is received via the vehicle detector VD whenthe parent controller is in its position or 6 the call will beremembered by the auxiliary period timer, by causing the relay LTD tobecome energized thus the up position may be called the memory position.

Let it now be assumed that the switch 150/ 150a is in its down positionwith contact 150 open and contact 150a closed.

The traffic control system illustrated in FIG. 3 is a system that couldemploy switch 150/ 1504 in its down position and obtain the desiredresults. The signals LG and LR of FIG. 6 would not be used on suchintersection control as shown in FIG. 3. The circuits would merely bedisconnected at leads 188 and 109 of FIG. 6. Further, the signals GX andRX would be similar to the signals GS and RS respectively of FIG. 3, andsignals GS and RS would be connected to the parent controller throughleads 211 and 213 respectively, all as shown in FIG. 3. The singlevehicle detector ND of FIG. 3 would be comparable to the vehicledetector VD of FIG. 6 while the vehicle detector SD of FIG. 3 would becomparable to vehicle detector NVD of FIG. 5.

Under this type of arrangement a call via actuation of the vehicledetector VD of FIG. 6 (or ND of FIG. 3) will effect the auxiliary periodtimer at all times except when the parent controller is in its positions5 and 6'. During positions 5' and 6' of the parent controller the lead211 would be energized to energize the relay XR of FIG. 7 through acircuit previously described. With relay XR of FIG. 7 energized itscontact 189 is opened and its contact 190 is closed, so that anactuation on the vehicle detector VD of FIG. 6 (or ND of FIG. 3) wouldbe completed to the parent controller supplying a ground connected fromground lead 75 through the closed contacts of vehicle detector VD, lead137, female receptacle F13 (all in FIG. 6) to FIG. 7 through male plugM13, lead 136, male plug M9 to FIG. 6 through female recep- 20 tacle F9,lead 135, contact 134 of relay TSR if relay T SR is deenergized, contact51a to lead 133, or if relay TSR is energized through contact 191 ofrelay TSR to lead 133 to female receptacle F7 to FIG. 7 through maleplug M7, lead 131, lead 132, contact 190 of relay XR, lead 192, contact150a, lead 194 to junction 195, male plug M2 to FIG. 6 through femalereceptacle F2, to lead 164 to a junction on the terminal strip TS tolead 214 which lead is connected to the parent controller of FIG. 5 aspreviously described, thereby putting a call into the parent controllerfor phase A. If the parent controller were in its position 6 at the timethe call is received the call would affect the parent controller and actto extend the vehicle interval as if the call had been received from thevehicle detector SD. Such call or calls during position 6' have theefiect of extending the vehicle interval to the maximum limit aspreviously described in connection with independent operation of theparent controller.

If, on the other hand, an actuation of the vehicle detector VD of FIG. 6(or ND of FIG. 3) should occur when the parent controller is in itspositions 1', 2, 3 or 4' such actuations would attect the auxiliaryperiod timer by energizing the relay LTD in FIG. 7, if such relay werein a deenergized condition. Such energizing circuit may be traced fromthe low voltage A.C. input in FIG. 6 through lead 123, contact 124 ofrelay TR, lead 125 to female receptacle F11 to FIG. 7 through male plugM11, lead 126, the coil of relay LTD, lead 127, lead 128, contact 189 ofrelay XR, lead 132, lead 131 to male plug M7 to FIG. 6 through femalereceptacle F7, lead 133, contact 51a of switch 51, contact 134 of relayTSR, lead 135, female receptacle F9 to FIG. 7 through male plug M9, lead136 to male plug M13 to FIG. 6 through female receptacle F13, lead 137,vehicle detector contact VD to grounded lead 75'.

Additional calls on the vehicle detector VD of FIG. 6 (or ND of FIG. 3)do not effect the auxiliary period timer once the relay LTD (of FIG. 7)has become energized.

When the parent controller moves into its position 5' and the auxiliaryperiod timer has registered a call, the timing power circuit of theparent controller is opened as previously described, and the signal GS,connected directly to the parent controller through lead 211, as shownin FIG. 3, -will be illuminated to give right-of-way to northboundtraffic on street C while the signal RS of FIG. 3 which is comparable tosignal RX of FIG. 6, is illuminated to hold the southbound trafiic onstreet C. At the termination of the timed period the signal RX (of FIG.6) or RS (of FIG. 3) will be extinguished and signal GX (of FIG. 6) orGS (of FIG. 3) will be illuminated.

The relay TSR of FIG. 6, may be used for remote selection of the timingpotentiometers 35 or 36. The switch 49 may be controlled locally orremotely by manual means or by a time clock or some master controlapparatus for selection between the two potentiometers 35 and 36. Whenthe relay TSR is deenergized so that contact is closed to placepotentiometer 35 in the charging circuit of the capacitor 38, thecontact 198 is also closed to complete the illuminating circuit for theindicator lamp 48 from the A.C. input through lead 105, lead 199, lamp48, contact 198 of relay TSR, lead 71, lead 66 to grounded lead 75.

If the energizing circuit for the relay T SR should he completed byclosure of the switch 49, the circuit, complete from an A.C. supply, forexample as shown in FIG. 6 through lead 105, lead 200, the coil of relayTSR, switch 49 to grounded lead 75, would cause the relay TSR to becomeenergized. The contact 80 of relay TSR would open and contact 81 ofrelay TSR would close. This reversal of contacts would eliminate thepotentiometer 35 from the charging circuit of the capacitor 38 andinsert potentiometer 36 into the charging circuit of ca- 21 pacrtor 38.The contact 198 of relay TSR would open extinguishing the lamp 48 andcontact 197 of relay TSR would close to complete a circuit to illuminatethe lamp 47 via a circuit that may be traced from the A.C. input throughlead 105, lead 199, lamp 47, contact 197 of relay TSR, lead '71, lead 66to grounded lead 75.

With the switch 51 in contact with contact 51a it is obvious that avehicle actuation across vehicle detector VD could be completed toenergize the relay LTR regardless of the condition of the relay TSR,through either contact 134 or 191.

If, however, the adjusting knob on the timing dial of the potentiometer35 were turned to the oif-position the switch 51, which is actuallylocated at the end of the shaft of potentiometer 35, would be reversedin position and would then be connected to the contact 51b. With therelay TSR deenergized so that its contact 134 is closed, an actuation ofthe vehicle detector VD would not energize the relay LTD but wouldsupply a ground to the lead 214 from the parent controller the circuitbeing traced from the grounded lead 75 back through the contacts VD,lead 137, to female receptacle F13 to FIG. 7 through male plug M13, lead136 to male plug M9 to FIG. 6 through female receptacle F9, lead 1135,contact 134 of relay TSR, contact 51b of switch 51, lead 52, femalereceptacle F8 to FIG. 7 through male plug M8, lead 53, through point195, male plug M2 to FIG. 6 through female receptacle F2, lead 164 to ajunction on the terminal strip TS to lead 214 to the parent controllerin FIG. to apply a ground connection to the detector relay ER which is,in effect, a call to phase A. Since the relay LTD did not becomeenergized the relays DR and LTR also remain tdeenergized and althoughthe parent controller receives a call for phase A the auxiliary periodtimer does not insert an auxiliary period into the cycle of the parentcontroller. Such actuation would be similar to an actuation of thevehicle detector NVD of FIG. 5 and cycle the parent controller if suchcontroller was not then in a position giving phase A the right-of-way. v

Attention is now directed to the preferred non-actuated embodiment ofthe auxiliary period timer as disclosed in the circuit diagram in FIG.6. It will be noticed that several of the leads terminating with thefemale receptacles are interconnected by the plug-in jumper assembly.The receptacle F7 is connected to receptacle F12 through male plug N7,lead 205 and male plug N12 and receptacle F9 is connected to receptacleF10 through male plug N9, lead 206 and male plug N10.

The non-actuated form of auxiliary period timer inserts a period intothe cycle of a parent controller, as does the actuated form, but theparent controller is not itself cycled by the action of the non-actuatedauxiliary period timer. The call circuits leading into the parentcontroller placing a ground on leads 214 and 215 (as previouslyexplained) are not connected to the plug-in assembly which forms part ofthe non-actuated period timer nor is the detector circuit of the basicunit connected through the plug-in jumper assembly.

The relay RR is energized in the non-actuated auxiliary period timereach time the parent controller moves into its position 2', the circuitbeing similar to that described relative to the actuated form ofauxiliary period timer. 9

With the relay RR energized, the relay LTR is energized through acircuit that may be traced from the A.C. supply through lead 105, lead170, the coil of relay LTR, lead 172, contact 174 of relay RR, point175, lead 176, receptacle F10, male plug N10, lead 206, male plug N9,receptacle F9, lead 135, contact 134 of relay TSR, if relay TSR isdeenergized, contact 51a of switch 51 to lead 133, or if relay TSR isenergized through its contact 191 to lead 133, receptacle F7, male plugN7, lead 205, male plug N12, receptacle F12, lead 207, contact 208 ofrelay TR, lead 71, lead 22 66 to grounded lead 75. When the relay LTRbecomes energized, it closes its contact 173 to shunt contact 174 ofrelay RR from the lead 172 to point 175 thereby locking-in through itsown contact.

It will be noticed that the energizing circuit for the relay LTR, whenrelay TSR is deenergized, follows through switch '51, if thepotentiometer 35 were turned down and the switch 51 were turned 01% sothat switch 51 would be in contact with contact 51b then the energizingcircuit for the relay LTR would not be complete since lead 52, which isconnected to contact 51b of switch 51 is not connected to any externalcircuit at receptacle F8.

With the relay LTR energized the timing power circuit of the parentcontroller would be interrupted, as previously described, relative tothe actuated form of auxiliary period timer when the relay RR becomesdeenergized (in posit-ion 5 of the parent controller).

The timed period would be inserted by the nonactuated auxiliary periodtimer, into the cycle of the parent controller and at the end of theperiod the relay TR would be energized, all as previously described.

With the energization of the relay TR its contact 208 is opened to openthe energizing circuit of the relay LTR. The relay LTR becomesdeenergized and the timing power supply circuit for the parentcontroller is again completed at contact 101 of relay LTR.

The relay TR becomes deenergized and closes its contact 208 so that whenthe relay RR is again energized the energizing circuit for the relay LTRwill be completed.

The changeover from the actuated form to the nonactuated form ofauxiliary periodytimer can be accomplished by removing the plug-in relayassembly (illustrated in FIG. 7) and inserting the plug-in jumperassembly without any change of wiring.

Although the description above is described relative to the use of oneauxiliary period timer, actuated'and non-actuated in combination with afull actuated twophase trafiic controller, as parent controller, suchdescription is not meant to limit the use of an auxiliary period timerto such combination.

An actuated auxiliary period timer or a non-actuated auxiliary periodtimer [may be used in association with a full actuated or asemi-actuated trafific controller, on either of its phases, or afull-actuated traffic controller operated as a semi-actuated controller,or a non-actuated traflic controller. The type of traffic controller,either actuated :or non-act uated, does not change or control the typeof auxiliary period timer, either actuated or non-actuated, used inassociation with such trafiic controller.

Attention is now directed to FIG. 5a, the alternate method of control ofparent timing. FIG. 5a thusj illus trating ta modification of the partof FIG. 5 in closed, broken line box in the lower night corner, ispresented with switch SW11 closed, relay TR deenergized and contact TRlof relay TR closed completing a circuit from the A.C. input through line20 .to'closed switch SW11,

closed contact "PR1 to line L10 to transformer XFR. In

FIG. 5a the lead 219 is not a part of the parent controller timingcircuit but is instead an output of the parent controller into theauxiliary period timer to be used for the 'energization of the relay TRwith the circuit following through contacts of the auxiliary periodtimer to lead 217 to the relay TR to ground.

The method of control of the timing used by the connections as shown inFIG. 5 requires certain relays in the auxiliary period timer to beenergized to open their contacts and open the circuit between input 20"which is connected to the auxiliary period timer via lead 219 and lead216 which is connected to the line L10 tothe transformer XFR. In suchcase, the contacts in the control circuit through the auxiliary periodtimer would normally be closed and open only to stop the timing of theparent controller. When the alternating method, as shown in FIG.

a, is used to control the timing in the parent controller in lieu of themethod illustrated in the broken line box in FIG. 5, the lead 219 servesas an output line of the parent controller for external control of relayTR by connection to lead 217 to energize relay TR which relay whenenergized opens its contact TR1 to interrupt the timing power supplycircuit of the parent controller. Such energization of the relay TRrequires completion of the energizing circuit within the auxiliaryperiod timer to effectively stop the timing of the parent controller.Thus the external circuit within the auxiliary period timer wouldnormally have an open circuit and normally keep the relay TRdeenergized.

When such timing control method as illustrated in FIG. 5a is employed,the lead 219 of the FIG. 5a (which would now be part of FIG. 5) sconnected between the AC. input lead of FIG. 5a (FIG. 5) and theterminal strip TS of FIG. 6. The normally open contact 187 of relay LTRof FIG. 6 maintains the open energizing circuit for relay TR of FIG. 5a.When the relay LTR is energized, during the inserted interval of theauxiliary period timer, the energizing circuit for the relay TR iscompleted from the AC. input in FIG. 5 through lead 20, lead 219 to FIG.6 to terminal strip TS, lead 98, contact 99 of relay RR, contact 187 ofrelay LTR, lead "196 to terminal strip TS, lead 217 to FIG. 5 to relayTR to ground. The relay thus energized would open its contact TR1 andopen the timing power supply circuit of the parent controller.

The preferred form of auxiliary period timer, both actuated andnon-actuated, provides for both forms of timing control of parenttiming, as described.

Although the description above, of the actuated form, related to anactuation of the vehicle detector associated with the auxiliary periodtimer while the parent controller was at rest, it is obvious that suchactuation may occur at any time during the cycle of the parentcontroller. If such actuation, to operate the auxiliary period timer,would occur when the parent controller is in its phase B positions(position 2', 3 or 4'), a call to phase B would not be completed to theparent controller because of open contact 154 of relay RR in the phase Bcall circuit. However, the subsequent phase A call would be the same aspreviously described.

It the switch 150/1501: were in its down position (contact 150 open andcontact 150a closed) and an actuation on the vehicle detector associatedwith the auxiliary period timer were received while the parentcontroller is in its position 5' or 6', such actuation would, aspreviously explained, effect the parent controller, not the auxiliaryperiod timer. However, it should be noted that under such circumstance aphase B call to the parent controller would not be completed since therelay XR of the auxiliary period timer would be energized and would thusprevent the energization of relay LTD. With the relay LTD remainingdeenergized its contact 158 in the phase B call circuit would remainopen.

It will be obvious to those skilled in the art that numerouscombinations of usage, too numerous to be individually mentioned here,are possible because of the great versatility and flexibility of theauxiliary period timer. In considering the many features, including thevariation of the time of the auxiliary period, the remote selectionbetween locally adjusted time controls, the fact that remote eliminationor inclusion of such period is possible, in both the actuated andnon-actuated forms, the fact that the actuated form may produce eitheran extension effect on the parent controller or a memory effect on theauxiliary period timer itself, via actuation of the vehicle detectorassociated with the auxiliary period timer, it is obvious that the manypossible combinations are inherent in the auxiliary period timer itselfwithout the necessity of employing different types of trafiiccontrollers, as parent controllers to obtain the variety of trafiiccontrol systems.

Although the preferred embodiment of the device has been described andillustrated,

including some of the 24 various forms, it will be understood thatvarious changes in the form, details and arrangements of parts,combinations thereof and mode of operation and usage may be made withoutdeparting from the spirit of the invention, Within the scope of theappended claims.

We claim:

1. In a traflic control system for the intersection of a plurality ofroads at least one of which has two approaches from substantiallyopposite directions and having the usual stop and go signals for therespective roads including a set of such stop and go signals for each ofsaid two approaches, said system also having a primary trailic signalcontroller for operating said signals through the usual traffic controlsignal cycle including go periods in sequence for the respective roadsand including one period for normally operating the go signals for bothof said two approaches and the stop signals for the other road; anauxiliary controller for cooperating with said primary controller tointerrupt temporarily the normal operation of the go signals to one ofsaid two approaches at the beginning of their go period and to hold thestop signal on said one approach of said two approaches while allowingoperation of the go signal on the other approach of said two approachesto provide an advance green period for said other approach, saidauxiliary controller including means for timing said advance greenperiod and for temporarily replacing the timing of said primarycontroller, said timing means including a plurality of individualmanually adjustable timing controls and means adapted for remote controlfor selecting one or another of said timing controls alternatively to beeffective for such timing for said advance green period.

2. A combination as in claim 1, and including indicator signal means forshowing which of said plurality of timing controls is effective for suchtiming.

3. A combination as in claim 1, and including a manually controlledselective device for preventing said auxiliary controller from soproviding said advance green period when a desired one of said pluralityof timing controls is selected, whereby the insertion or omission of theadvance green period maybe remotely controlled.

4. A combination as in claim 1, and which includes tratfic actuatedmeans for controlling the operation of said auxiliary controller to soinsert said advance green period only in response to traffic actuationthereof.

5. A combination as in claim 1, and which includes traffic actuatedmeans for the approach to which the advance green is to be accorded forcontrolling the insertion of said advance green period by said auxiliarycontroller in response to traflic actuation, and manually controlledselective means for alternatively connecting said tr-aific actuatedmeans to so control said auxiliary controller and connecting saidtraflic actuated means directly to prolong the go period of the primarycontroller for said last named approach.

6. An auxiliary period timer for operation with a primary traffic signalcontroller for inserting a timed auxiliary signal period in the signalcycle of said primary controller, said signal period including a gosignal operated in one direction and a stop signal operated in theopposite direction at the beginning of the normal period for operationof go signals in both said one direction and said opposite direction,when operated therefor, said period timer including a trafiic actuatedrelay means plugjack mounted therein for so operating said auxiliaryperiod timer for providing said signal period in response to trafficactuation, and an auxiliary plug-jack connection means for replacementof said traffic actuated relay means for so operating said auxiliaryperiod timer for providing said signal period cyclically in said signalcycle without traffic actuation.

7. An auxiliary period timer as in claim 6 and including a plurality ofindividually adjustable timing means for timing said auxiliary signalperiod when selected, and electromagnetic means adapted for remotecontrol for selection of a desired one at a time of said individuallyadjustable timing means .for providing ditferent timing at selectedtimes.

8. An auxiliary period timer as in claim 7, and including meansassociated with one of said adjustable timing means and manuallysettable for effectively omitting said auxiliary period from the signalcycle when said one timing means is selected for control of saidauxiliary period timer.

9. An auxiliary period timer for operation with a primary trafiic signalcontrol er having a cycle of trafiic signal periods and, said auxiliaryperiod means controlled by said primary controller for operating saidtimer to interrupt the normal said cycle of said primary controller andinsert an auxiliary signal period at a particular part of said cycle, aplurality of individually adjustable timing means for supersedingtemporarily the operation of said primary controller and for timing saidauxiliary signal period when selected, and means for remote control forselection of a desired one at a time of said individually adjustabletiming means, and means individually associated with said timing meansby said selecting means for indicating which of said timing means is soselected for such timin 10. An auxiliary period timer as in claim 9, andin which said means controlled by said primary controller for sooperating said auxiliary period timer for inserting said auxiliarysignal period includes a circuit including plug-jack connectionterminals in said timer requiring cross connection for so operating saidtimer, and cooperating plug-jack means for providing said crossconnection.

11. An auxiliary period timer as in claim 10 and in which saidcooperating plug-jack connection means includes optional first alternatemeans for direct crossconnection for insertion of said auxiliary periodcyclically in the cycle of said primary controllers and second alternatemeans including relay means for providing said cross connection inresponse to actuation by traflic controlled by said auxiliary signalperiod, whereby one or the other of said alternate means may be employedto'convert from direct non-actuated control of insertion of saidauxiliary period to traffic actuated control of such insertion.

12. An auxiliary signal controller for providing a timed signal periodin cooperation with and in a particular part of the signal control cycleof a primary traffic signal controller providing successive go signalperiods for operation of traffic signals for interfering trafiicmovements and with the usual corresponding stop signal periods inconnection therewith, said primary controller having output circuits foroperation of the respective go and stop signals for providing normallyin its cycle the respective go and stop signal periods and having atiming control circuit for timing such periods, said auxiliarycontroller including input circuit means and first relay means connectedthereto for connection to one of said stop signal control outputcircuits of the primary controller for control of said first relaymeans, further input circuit means in said auxiliary controller forconnection to a go signal control output circuit in said primarycontroller for a traffic movement controlled by said last named stopsignal control output circuit, second relay means and input circuitmeans therefor in said auxiliary controller and including a [contact ofsaid first relay means for control of said second relay means, outputcircuit means in said auxiliary controller for operation of a desiredstop signal for said timed signal period and including contacts of saidfirst and second relay means for control of said last named outputcircuit for operation of said desired stop sign-a1, [further outputcircuit means in said auxiliary controller and including a contact onsaid second relay means for connecting said further output circuit meansto said further input circuit means for operation of a desired go signalwhen said further input circuit means is timer including 26 controllerexcept during said rtimed signal period, timing means in said auxiliarycon troller for timing said timed signal period and having an operatingcircuit for said timing including further contacts of said first andsecond relay means, and said timing means having means operated at theend of its timing of said timed signal period for controlling operationof said second relay means for reversing its contacts to switch [fromsaid desired stop signal controlling output circuit to said furtherdesired go signal controlling output circuit and to stop its timing, andadditional circuit means in said auxiliary controller includingadditional contacts of said first and second relay means for connectionwith said timing control circuit of said primary controller to stop thetiming of said primary controller during the timed signal period of saidauxiliary controller and to permit the timing of said primary controllerto continue at other times.

13. An auxiliary signal controller as in claim 12, and in which saidtiming means in said auxiliary controller includes a plurality of timingadjustment means, and additional realy means adapted for externalcontrol for selection between said timing adjustment means for effectingthe timing of its timed signal period.

14. An auxiliary signal controller as in claim 13, and includingindicator means and circuit means therefor including contacts on saidadditional relay means for selectively operating said indicator means toindicate which of said timing adjustment means is effecting said timing.

='l5. An auxiliary signal controller as in claim 14, and includingswitch means associated with one ofsaid timing adjustment means forselectively connecting and disconnecting said second relay means forpermitting its such operation and preventing its such operation, wherebysaid timed signal period of said auxiliary controller may be eifectivelypermitted in the signal cycle or omitted therefrom by external controlalong with selection of the associated timing adjustment means.

16. An auxiliary signal period controller as in claim 12 and in 'Whichthe operating circuit means for said second relay means includes outputand input terminal connections in said auxiliary controller and aremovable cross-connection means for connecting between the lastmentioned output and input terminal connections.

17. An auxiliary signal period controller as in claim 12 and in whichthe operating circuit means for said second relay means includes outputand input terminal connections in said auxiliary controller and aremovable cross-connection means for connecting between the lastmentioned output and input terminal connections, and furthercross-connection means for substitution for the first cross-connectionmeans and including further relay means for controlling operation ofsuch second relay means in response to actuation by traflic in a trafiicmovement permitted to proceed during said timed signal period of saidauxiliary controller.

18. An auxiliary signal period controller as in claim 16 and furthersaid cross-connection means including further relay means forcontrolling operation of said second relay means in response toactuation by traific in a trail-1c movement permitted to proceed duringsaid timed signal period of said auxiliary controller, and saidauxiliary controllerhaving a terminal for trafiic actuated device, and acorresponding connecting terminal in said cross-connection means forconnecting said traffic actuated, device to said further relay means forsuch traflic actuated control of the latter.

19. An auxiliary signal period controller as in claim 12 and in whichsaid primary controller is traflic actuated, and said auxiliarycontroller includes traific actuated means for controlling operation ofsaid second relay means for so prowiding said timed signal period, andtimed relay means controlled by said last mentioned traffic actuatedmeans for simulating trafiic actuation of energized by the primaryconnection of an external 27 said primary controller -to cause it toproceed to said par- 2,133';157 ticular part of its cycle. 2,750,5762,834,001 References Cited 1n the file of thls patent 2,883,643 UNITEDSTATES PATENTS 5 2,883,644 2,105,443 Renshaw Jan. 11, 1938 2,883,645

28 Turner Oct. 11, 1938 Beaubien June 12, 1956 Wilcox May 6, 1958 DuVivier Apr. 21, 1959 Barker Apr. 21, 1959 Du V-ivier Apr. 21, 1959

1. IN A TRAFFIC CONTROL SYSTEM FOR THE INTERSECTION OF A PLURALITY OFROADS AT LEAST ONE OF WHICH HAS TWO APPROACHES FROM SUBSTANTIALLYOPPOSITE DIRECTIONS AND HAVING THE USUAL STOP AND GO SIGNALS FOR THERESPECTIVE ROADS INCLUDING A SET OF SUCH STOP AND GO SIGNALS FOR EACH OFSAID TWO APPROACHES, SAID SYSTEM ALSO HAVING A PRIMARY TRAFFIC SIGNALCONTROLLER FOR OPERATING SAID SIGNALS THROUGH THE USUAL TRAFFIC CONTROLSIGNAL CYCLE INCLUDING GO PERIOD IN SEQUENCE FOR THE RESPECTIVE ROADSAND INCLUDING ONE PERIOD FOR NORMALLY OPERATING THE GO SIGNALS FOR BOTHOF SAID TWO APPROACHES AND THE STOP SIGNALS FOR THE OTHER ROAD; ANAUXILIARY CONTROLER FOR COOPERATING WITH SAID PRIMARY CONTROLLER TOINTERRUPT TEMPRARILY THE NORMAL OPERATION OF THE GO SIGNALS TO ONE OFSAID TWO APPROACHES AT THE BEGINNING OF THEIR GO PERIOD AND TO HOD THESTOP SIGNAL ON SAID ONE APPROACH OF SAID TWO APPROACHES WHILE ALLOWINGOPERATION FO THE GO SIGNAL ON THE OTHER APPROACH OF SAID TWO APPROACHESTO PROVIDE AN ADVANCE GREEN PERIOD FOR SAID OTHER APPROACH, SAIDAUXILIARY CONTROLLER INCLUDING MEANS FOR TIMING SAID ADVANCE GREENPERIOD AND FOR TEMPORARILY REPLACING THE TIMING OF SAID PRIMARYCONTROLLER, SAID TIMING MEANS INCLUDING A PLURALITY OF INDIVIDUALMANUALLY ADJUSTABLE TIMING CONTROLS AND MEANS ADAPTTED FOR REMOTECONTROL FOR SELECTING ONE OR ANOTHER OF SAID TIMING CONTROLSALTERNATIVELY TO BE EFFECTIVE FOR SUCH TIMING FOR SAID ADVANCE GREENPERIOD.